Iron hexafluorophosphate complexes

Fe(mtz)J(PF6)2. The solid iron(II) complex hexafluorophosphate of the ligand mtz = 1-methyltetrazole shows a gradual transition which is... 

Experimental Procedure 2.1.3. Preparation of an Iron Carbene Complex by a-Abstraction of Hydride Dicarbonyl(T 5-cyclopentadienyl)(phenylthiocarbene) iron hexafluorophosphate [179]... 

The cyclic, cationic iron carbene complex 6 can be prepared and isolated if the counterion is a nonhalide species, such as hexafluorophosphate or tetrafluoroborate95 Treatment of com-... 

Hydride abstraction from dienyl tricarbonyl iron complexes furnishes cationic dienyl tricarbonyl iron complexes. For example, reaction of the diene-iron tricarbonyl complex (115) with triphenyhnethyl hexafluorophosphate followed by trimethylsilyl cyanide furnished with excellent regio- and stereoselectivity a new diene iron tricarbonyl complex (116) (Scheme 170). Excellent regio- and stereoselectivity is seen upon reaction of the cationic complex (116) with trimethylsilyl cyanide (TMS-CN) (Scheme 170). Reduction of the nitrile affords a spirocyclic lactam complex. Intramolecular cyclization of in situ formed enols furnishes spirocyclic compounds again with excellent stereoconfrol (Scheme 171). An interesting example of hydride transfer from a cyclohexadiene ring to a pendant aldehyde followed by nucleophilic addition is seen in Scheme 172. 

The iron(II) complex XIII crystallizes as the bis(hexafluorophosphate) salt with acetonitrile as the fifth, axial, ligand. This composition appears to be dictated largely by the relative solubilities of the salts of the possible anions in the mixed solvent. Most of the iron(II) lacunar complexes crystallize as the chloride hexafluorophosphate mixed salts, in which the chloride occupies the axial site. The complex is high spin and Five coordinate in the solid state and in coordinating solvents. In N-methylimidazole at 20 °C the title complex binds dioxygen reversibly with = 0.0012 torr . In 3 1 1 acetone-N-methylimidazole-water the half-life toward irreversible auto-xidation is 24h at room temperature. This complex constitutes the First example of a nonporphyrin iron(II) complex that can act as a dioxygen carrier at room temperature. ... 

High-frequency shoulders on Vs(CO) and Vas(CO) bands in the FTIR spectra of an organometallic probe derived from tricarbonyl(l-4- n -5-pyridinocyclohexa-l,3-diene)iron hexafluorophosphate have been observed io on incubation with a-chymotrypsin and were assigned to an iron-complex covalently bonded to enzyme-NH2 groups. Curve-fitting analysis of the spectra enabled the bound complex to be detected even in the presence of the unbound probe and its FTIR spectrum to be calculated and compared with spectral data arising from similar interactions between the tricarbonyliron moiety and twelve aminoacids and polylysine. 

Most recently, Cramer and Jenkins have developed a novel tetracarbene iron(ll) complex 8, which was readily prepared by the reaction of the macrocyclic tetraimidazolium 7 with iron(ll) iodide using lithium diisopropylamide followed by the addition of thallium hexafluorophosphate (Scheme 2.12) [18]. Employing this catalyst system, aziridination reactions of various types of substituted aliphatic alkenes including trisubstituted and tetrasubstituted ones with both electron-donating and electron-withdrawing aryl azides were achieved. One advantage of this methodology is... 

A carbon-iron bond is also formed by the reaction of the cyclopropenium salt 185 with dicarbonyl(i/5-cyclopentadienyl)(trimethylsilyl)iron [92], (Scheme 69) In the reaction with benzocyclobutenylidene- 5-cyclopentadienyliron(II) hexafluorophosphate 186, CpFe(CO)2R (R=cyelo-C3H5, CH2-cyclo-C3H5) is converted to the allene and butadiene complexes, 187 and 188, respectively [93]. (Scheme 70)... 

Decomplexation of some metal complexes calls for drastic conditions. This is true for (/7-arene)(/7-cyclopentadienyl)iron(II) hexafluorophosphates, [FeAr(Cp)][PF6] [54, 55]. Although their chemical decomplexation is known [55 a], the most widely used method is pyrolytic sublimation at high temperatures (>200 °C) [55 b]. To evaluate MW irradiation as the method of decomplexation of such iron complexes, Roberts et al. performed the reaction in the presence of graphite [54]. They discovered that the yield of the free ligand from the [Fe( -N-phenylcarbazole)( -Cp)][PF6] complex (43) depended on the kind (flakes or powder) and amount of graphite, and on the irradia-... 

Dissertation Washington University St. Louis, 1979]. From data for the analogous cobalt(III) complex with perchlorate and hexafluorophosphate as anions, he found association constants of about 900 and 300, with distances of closest approach of 5 or 6 8, respectively. These values seem reasonable. For the iron(II) compound with the hexafluorophosphate or perchlorate, the ion association constants were too small to measure (< - 50). 

The iron-mediated synthesis of 2-oxygenated carbazole alkaloids is limited and provides only a moderate yield (11%) for the oxidative cyclization to 2-methoxy-3-methylcarbazole using iodine in pyridine as the reagent [90]. Ferricenium hexafluorophosphate is the superior reagent for the iron-mediated arylamine cyclization leading to 3-oxygenated carbazoles (Scheme 12). Electrophilic substitution of the arylamines 16 with the complex salt 6a leads to the iron complexes 17. Oxidative cyclization of the complexes 17 with an excess of ferricenium hexafluorophosphate in the presence of sodium carbonate affords... 

Direct formation of an organometallic complex 81 resulted when (r) -o-dichlorobenzene)(T) -cyclopentadienyl)iron(II) hexafluorophosphate was reacted with 4-methylbenzene-1,2-dithiol. The free 2-methylthianthrene could be released by heating the complex to 200-250°C (82JHC801). 4,5-... 

Alternatively, using the iron-mediated arylamine cyclization, a short access to carazostatin (247), albeit in lower yield, was achieved. The oxidation of the complex 714 with ferricenium hexafluorophosphate in the presence of sodium carbonate... 

An alternative method for the oxidative cyclization of the arylamine-substituted tricarbonyl(r -cyclohexa-l,3-diene)iron complex (725) is the iron-mediated arylamine cyclization. Using ferricenium hexafluorophosphate in the presence of sodium carbonate provided hyellazole (245) directly, along with the complex 727, which was also converted to the natural product (599,600) (Scheme 5.71). 

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